iwlwifi: remove unneeded locks from apm_stop() and stop_master()

Since priv->reg_lock was added to keep multi-access register manipulation
atomic, priv->lock protection is no longer needed.  Remove this from
iwl_apm_stop_master() and iwl_apm_stop().

Add warning of timeout when polling for busmaster disablement confirmation,
and some comments.

NOTE:  This is needed to enable use of apm_ops.stop() within iwl_eeprom_init();
priv->lock does not get initialized until after this flow.  See patch
"remove power-wasting calls to apm_ops.init()"

Signed-off-by: Ben Cahill <ben.m.cahill@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/iwlwifi/iwl-core.c b/drivers/net/wireless/iwlwifi/iwl-core.c
index d2b56baf98fb33215baf24bca5a85863ab505eef..4808f66611608a7b281767f1631e661bc1eecc13 100644 (file)
--- a/drivers/net/wireless/iwlwifi/iwl-core.c
+++ b/drivers/net/wireless/iwlwifi/iwl-core.c
@@ -1353,39 +1353,39 @@ EXPORT_SYMBOL(iwl_irq_handle_error);
 
 int iwl_apm_stop_master(struct iwl_priv *priv)
 {
-       unsigned long flags;
-
-       spin_lock_irqsave(&priv->lock, flags);
+       int ret = 0;
 
-       /* set stop master bit */
+       /* stop device's busmaster DMA activity */
        iwl_set_bit(priv, CSR_RESET, CSR_RESET_REG_FLAG_STOP_MASTER);
 
-       iwl_poll_bit(priv, CSR_RESET, CSR_RESET_REG_FLAG_MASTER_DISABLED,
+       ret = iwl_poll_bit(priv, CSR_RESET, CSR_RESET_REG_FLAG_MASTER_DISABLED,
                        CSR_RESET_REG_FLAG_MASTER_DISABLED, 100);
+       if (ret)
+               IWL_WARN(priv, "Master Disable Timed Out, 100 usec\n");
 
-       spin_unlock_irqrestore(&priv->lock, flags);
        IWL_DEBUG_INFO(priv, "stop master\n");
 
-       return 0;
+       return ret;
 }
 EXPORT_SYMBOL(iwl_apm_stop_master);
 
 void iwl_apm_stop(struct iwl_priv *priv)
 {
-       unsigned long flags;
-
        IWL_DEBUG_INFO(priv, "Stop card, put in low power state\n");
 
+       /* Stop device's DMA activity */
        iwl_apm_stop_master(priv);
 
-       spin_lock_irqsave(&priv->lock, flags);
-
+       /* Reset the entire device */
        iwl_set_bit(priv, CSR_RESET, CSR_RESET_REG_FLAG_SW_RESET);
 
        udelay(10);
-       /* clear "init complete"  move adapter D0A* --> D0U state */
+
+       /*
+        * Clear "initialization complete" bit to move adapter from
+        * D0A* (powered-up Active) --> D0U* (Uninitialized) state.
+        */
        iwl_clear_bit(priv, CSR_GP_CNTRL, CSR_GP_CNTRL_REG_FLAG_INIT_DONE);
-       spin_unlock_irqrestore(&priv->lock, flags);
 }
 EXPORT_SYMBOL(iwl_apm_stop);